German Patent Application No. 43 25 842 describes a conventional fuel injector, in which a valve closing element formed on a valve needle interacts with a valve seat surface to form a sealed seat. In order to lift the valve closing element of the valve needle from the valve seat surface, an armature is provided on the valve needle, which interacts with an electrically excitable magnetic coil to open the fuel injector. The fuel exits the fuel injector in the form of a fuel stream which partly hits the wall of the intake tube and the inlet valve of the internal combustion engine, where condensation of the injected fuel can occur in the cold state of the internal combustion engine or in case of a sudden change in load. Furthermore, the fuel injector can be exposed to a non-uniform operating temperature due to power dissipation of the magnetic coil.
German Patent Application No. 44 38 335 describes counteract wall wetting of the intake tube, where a wall of the intake tube is electrically heated using of a Peltier element to evaporate the fuel that impacts there. Using the Peltier element is advantageous (in comparison to using a conventional heating element, e.g., a PTC resistor element) since significantly lower heating output is required.
German Patent No. 20 57 972, and German Patent Application Nos. 28 43 534 and 30 17 591 describe methods to heat the fuel injected by the fuel injector. German Patent No. 20 57 972 describes a heating element provided in the fuel injector for heating the fuel, with the fuel flowing around the fuel injector. German Patent Application No. 28 43 534 describes connecting the injector with a fuel exit opening using an exit channel and arranging a heating element in the exit channel, which heats the fuel flowing through the exit channel. German Patent Application No. 30 17 591 describes an injector having a valve housing surrounded by a ring-shaped or tube-shaped heating cartridge, which is thermally connected with the valve housing. For heating the fuel, additional electrical heating power must be provided in the German Patent Applications described above.